the synthesis of quinazolinones, quinoxalinones, benzooxazinones, and benzothiazoles from the reactions of α-keto acids with 2-aminobenzamides, benzene-1,2-diamines, 2-aminophenols, and 2-aminobenzenethiols, respectively, is described. The reactions were conducted under catalyst-free conditions, using water as the sole solvent with no additive required, and successfully applied to the synthesis of sildenafil
A niobium-catalyzed coupling reaction of α-keto acids with <i>ortho</i>-phenylenediamines: synthesis of 3-arylquinoxalin-2(1<i>H</i>)-ones
作者:Camila Ebersol、Nicole Rocha、Filipe Penteado、Márcio S. Silva、Daniela Hartwig、Eder J. Lenardão、Raquel G. Jacob
DOI:10.1039/c9gc02662b
日期:——
valuable 3-arylquinoxalin-2(1H)-ones was developed, by the reaction of α-keto acids with ortho-phenylenediamines in the presence of ammonium niobium oxalate (ANO) as a catalyst. The reactions were conducted in only 10 min under ultrasonic irradiation as an alternative energy source, affording water as the only co-product. A total of twenty-three different 3-arylquinoxalin-2(1H)-ones were selectively obtained
在草酸铌铵(ANO)存在下,通过α-酮酸与邻苯二胺的反应,开发了一种获得有价值的3-芳基喹喔啉-2(1 H)-酮的通用方法。作为替代能源,在超声辐射下仅需10分钟即可进行反应,仅提供水作为副产物。通过该原子有效方案,以良好至优异的产率选择性地获得了总共二十三种不同的3-芳基喹喔啉-2(1 H)-。另外,使用1 H– 15 N HMBC实验来揭示所得产物的区域异构现象。
Visible-light-induced, copper(i)-catalysed C-N coupling between o-phenylenediamine and terminal alkynes: one-pot synthesis of 3-phenyl-2-hydroxy-quinoxalines
and terminal acetylenes was performed using simple copper(I) chloride as a catalyst for the synthesis of quinoxaline derivatives. The current method works well for a wide range of electron rich as well as electron poor group-substituted o-phenylenediamines and phenylacetylenes. The key component in the reaction is the direct photo-excitation of in situ generated copper arylacetylide (λabs = 420–480 nm)